1. Technical Field
The present invention relates to a battery pack, which is applicable to a power supply of a portable personal computer, for instance. The present invention enables a more thickness reduction in the battery pack of the personal computer etc. as compared with a conventional technology to be attained by holding sheet-shaped secondary battery cells in a multi-layered arrangement with the same-side surfaces facing each other.
2. Background Art
Conventionally, a portable personal computer is adapted to be carried for being used in various places, and is thus fabricated in a small-sized configuration and further in a small-thickness configuration so as to be convenient to carry.
Accordingly, the personal computer is also adapted to hold a driving battery pack in an exchangeable condition, so that an exchange of the battery pack is effected as needed to prevent the personal computer from being placed into a difficult condition in use by running-down of a battery. In addition, the battery pack is also given in a small-thickness configuration to prevent portability from being degraded.
Thus, the battery pack of this kind is configured by a series-parallel connection of secondary battery cells specified as constituent units of the battery pack depending on a supply voltage and a power supply capacity required for the personal computer. Further, in the battery pack, the secondary battery cells are given in the form of a sheet to provide a multi-layered arrangement and further to provide a parallel arrangement so as to meet the series-parallel connection of these secondary battery cells.
By the way, in the battery pack of this kind, there has been a demand for a more thickness reduction.
The battery pack, however, provides the series-parallel connection of more than one secondary battery cell at an inside as needed, so that a complicated connection at the inside is required, and as a result, a remarkable degradation of productivity is predicted, in a case where size and thickness reductions of the battery pack are carried forward in the present situation.